Time Dependent Properties for {Concrete, Tendons} Form

Use the Time Dependent Properties for Concrete form to choose CEB-FIP 90, CEB-FIP 2010, ACI 209R-92, or User and then, where needed, specify the Compressive Strength and Stiffness, Creep, and Shrinkage factors for the material definition.

Simple scale factors may be specified to adjust the time-dependent concrete behavior for the purpose of performing sensitivity studies. The scale factor on the modulus of elasticity directly multiplies the Young’s modulus and shear modulus of the material for any staged-construction load case that considers time-dependent behavior, and consequently affects dependent load cases. No other load cases are affected. The scale factors on creep and shrinkage directly multiply the corresponding creep or shrinkage strains computed during any time-dependent staged-construction load case.

Use the Time Dependent Properties for Tendons form to choose CEB-FIP and then specify if time dependence is to be considered for Prestressing Steel Relaxation, the relaxation analysis type, and the CEB-FIP class, where appropriate.

When selecting the User option, full control is given for defining the following data:

Stiffness versus age, defined as a multiplier of the material modulus of elasticity.
Creep coefficient versus days since loading, for multiple ages at loading. Interpolation will be used between the different age at loading curves.
Shrinkage strain versus age.

A simple scale factor may be specified to adjust the time-dependent tendon behavior for the purpose of performing sensitivity studies. The scale factor directly multiplies the relaxation strain computed during any time-dependent staged-construction load case.

Click the Show Plot button on the forms to display the Material Property Time Dependence Plot form.

Material Name, Material Type, Symmetry Type and Property Temperature display boxes. These display boxes identify the material name and type, and the directional symmetry and property temperature (if any has been specified) for the material property definition as specified using the Material Property Data form.
Show Plot button. Click this button to access the Material Property Time Dependent Plot form. Use the form to view a plot of the temperature dependent property definition.

After the time dependent properties have been specified as part of the material property definition, they will be applied to those area(s), frame(s),and tendon(s) whose section properties use these materials. For areas, only homogeneous shell (thin and thick) section properties are considered..

Access the Time Dependent Properties for {Concrete, Tendons} form as follows:

Click the Define menu > Materials command to display the Define Materials form. The Define Materials form also can be accessed by clicking the + (plus) symbol that may appear next to a drop-down list of available materials, such as the Material drop-down list on the Shell Section Data form, or the {Frame Section Type} Data forms.
Check the Show Advanced Properties check box.
Click the Add New Material button to display the Material Property Options form.
Select Concrete or Tendon in the Material Type drop-down list.
Click the Modify/Show Material Properties button to access the Material Property Data form.

Note that if the Material Properties are Temperature Dependent check box is checked when the Modify/Show Material Properties button is clicked, the Temperature Dependent Material Properties form will display; click the appropriate button to access the Material Property Data form
Click the Time Dependent Properties button.